M3 3-inch Anti-Aircraft Artillery

Early in World War II, the M3 3-inch (76.2 mm) Anti-Aircraft Gun was the standard medium AAA until the 90mm Anti-Aircraft Gun was available in quantity. The M3 3-in. gun used the same M2 (or M2A1 or M2A2) carriage as the Bofors 40mm antiaircraft gun, with an axle and wheels at each end and four long stabilizing outriggers that folded for travel. The gun platform, when its folded sections were deployed, supported the crew while allowing for 360° traverse of the gun.

The M3 3-inch AAA could hit an aerial target at a maximum horizontal range of 14,780 yards and could reach just below a 10,000-yard ceiling, firing its 12.87-pound HE rounds at up to 25 rounds per minute. The same gun was initially used in shipboard and ground installations and used the same ammunition as the M5 3-in. anti-tank gun. As with other AA artillery, the gun was used against ground targets when the tactical situation called for it. Both the Army and the USMC were equipped with the M3 3-inch Anti-Aircraft Artillery until it was replaced by the 90mm AAA in mid-1942.

M3 3-inch Anti-Aircraft Artillery emplacement on Corregidor before its fall to the Japanese in 1942.

No. 2 Gun Crew, Btry D, 208th CA AA with their M3 3-inch Anti-Aircraft Gun at New Fighter Strip, Dobodura near Buna, New Guinea, 17 May 1943.